El Capitan's single most transformative feature is the overhaul given to Mission Control, a revamp that also affects Spaces and the Full Screen mode. It feels like a marriage of OS X's window management and some of Windows 10's more promising new features, driven by Macs' large, accurate trackpads. The fact that Windows 10’s window management and multitasking features borrow so much from the Mac means that comparisons are inevitable.

Start by swiping three fingers upward to open Mission Control. This should look broadly familiar save for a couple of tweaks. You don’t see thumbnails of all your open desktops and full screen apps at the top unless you move the mouse pointer up there, only text labels. And windows from the same app are no longer stacked atop one another by default, but displayed separately (this was an option in older OS X versions, it's just the default behavior now). If you have a bunch of Chrome or Safari windows open at once, you know this could be annoying in Yosemite—Mission Control becomes way less useful if you can’t actually see the window you’re opening. If you prefer the old behavior, you can still enable it in the Mission Control settings, but it's off by default.

You can still use Mission Control pretty much the way you did before. Switch between windows, open and close spaces, drag windows from one desktop to another, and drag spaces between multiple monitors. The biggest new feature is Split View, which places two full screen apps side by side in a way that looks a whole lot like that iPad multitasking feature from iOS 9.

There are a few different ways to do this. Long-click the green stoplight button of an app that supports full screen mode, and the OS will ask you to drag it to the left or right half of the screen. A mini-Mission-Control-type collection of your other windows will then fill the other half of the screen. Apps that can take advantage of Split View will look like they normally do, while those that can’t do it will appear faded. Click an app and you’ll see them both side by side, divided by a vertical black line.

You can also put an app into full screen mode as you normally would, open Mission Control, and drag another full screen app over top of the first app to create a Split View. Unlike in iOS, you can put two separate windows from the same app side-by-side if you need to compare two Word documents or Safari windows.

That black line can be clicked and dragged to change how much space each app takes up. The default view is 50/50, but most apps support a 25/75 split (though some, like Calendar, won’t shrink down that far). iOS enforces those strict 50/50 and 25/75 splits, but in OS X the divider can go pretty much anywhere as long as the app supports it. 60/40, 57/43, whatever you want.

From there, work with the apps (and take them out of full screen mode) just as you would have before. This feature isn't exactly necessary in an OS with full support for traditional windowed multitasking, but for people like me who like to use full screen mode to reduce clutter or to ease the pain of working on one small laptop screen instead of a big multi-monitor desktop rig, there's definitely some utility here.

This is all a bit easier to learn by watching rather than by reading, so refer to the embedded video above. Other tricks: drag a window to the top of the screen and hold the cursor there for a second to invoke Mission Control (this was unreliable in early betas but is easier and more consistently invoked in the final build). And shake the mouse cursor a couple of times to make it larger and easier to find, a smart tweak if you frequently lose the cursor on those multi-monitor setups.

If there's one thing that makes the new Mission Control a bit less usable than the old one, it's that showing app windows individually instead of by group strips them of the icon and label that told you, in quick and unmistakable terms, what app you were looking at. El Capitan only shows you a text label if you hover the cursor over the window. Also, not all apps that support full screen mode will automatically support Split View, though again this has improved since the early betas. Judging from the documentation, it looks like developers will need to use Auto Layout to take advantage of the feature. If your app's developer isn't on board, the feature becomes less useful.

Andrew Cunningham
Andrew has a B.A. in Classics from Kenyon College and has over five years of experience in IT. His work has appeared on Charge Shot!!! and AnandTech, and he records a weekly book podcast called Overdue. Twitter@AndrewWrites